# CVE-2026-89632

## Summary

- **CVE ID:** CVE-2026-89632
- **Severity:** HIGH
- **CVSS Score:** 8.2 (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:H)
- **CWE:** N/A
- **Published:** Sep 11, 2026
- **Last Modified:** Sep 13, 2026

## Description

In the Linux kernel, the following vulnerability has been resolved:

smb: client: fix use-before-check of ReparseDataLength in reparse_buf_ptr()

reparse_buf_ptr() reads buf->ReparseDataLength before checking that
count covers the full fixed header:

    buf = (struct reparse_data_buffer *)((u8 *)io + off);
    len = sizeof(*buf);                          /* 8 bytes */
    rdlen = le16_to_cpu(buf->ReparseDataLength); /* offset 4, 2 bytes */

    if (count < len || count < rdlen + len)      /* check comes after */

struct reparse_data_buffer has ReparseDataLength at offset 4.  If a
server returns OutputCount < 6, the read at offset 4-5 reaches past
the end of the received data.  The off+count bounds against iov_len
were already validated, but that does not protect against count being
smaller than sizeof(*buf).

Split the check: verify count >= sizeof(*buf) before reading
ReparseDataLength, then verify count covers the data region.

## Affected Products

- Linux — Linux (a158bb66b1373866d9fd5997565a58a573085539)
- Linux — Linux (6.6.32)

## References

- [CNA](https://git.kernel.org/stable/c/711cf71300d7992f450600df8864917d3538679f)
- [CNA](https://git.kernel.org/stable/c/05f78e6cf34ea3a285053bd5999e08e8ac298bd5)

## Exploitation Prediction (EPSS)

- **EPSS Score:** 0.32%
- **EPSS Percentile:** 24.8

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_Exported from OnDuty AI Vulnerability Intelligence on 2026-09-18._